Codification of the economic substance doctrine in 2010 ushered in a new phase in the debate regarding the meaning and reach of the doctrine. The main statutory hint as to the intended scope of the codified economic substance doctrine is ambiguous, providing, “The determination of whether the economic substance doctrine is relevant to a transaction shall be made in the same manner as if this subsection had never been enacted.” This Article argues that this language should be read in light of the codification history, which stretches back for over ten years before enactment. This history suggests that the relevance provision is primarily about maintaining the precodification balance of decision making between tax agencies and courts. The history also indicates that the provision reflects congressional concurrence in the precodification trajectory of the doctrine, particularly in terms of the types of transactions that were being litigated. The movement from the common law to codified statute brought with it the potential application of a complex web of authority regarding interactions between tax agencies and courts in their administration, enforcement, and interpretation of the Code. Included in that web is the general ability of the tax agencies to obtain strong deference from the courts as to the agencies' authoritative, reasonable interpretations of textual ambiguities. The economic substance legislative history acknowledges the general interpretive authority of the tax agencies but does not suggest a specific path for reconciling that authority with the requirement that development of the doctrine continue “in the same manner” as under the common law. This Article proposes that *552 the various strands in the legislative history can be reconciled by interpreting the relevance provision as adding two directions to tax agencies and courts: (1) the statute does not apply to transactions that are clearly consistent with the form and purpose of claimed tax benefits and (2) the courts have final discretion over whether a specific, litigated transaction ultimately fails the requirements of the economic substance doctrine.